Effects of ranitidine on ventricular refractory period and fibrillation threshold of normal and ischemic ventricle in rabbits
Qiu, H.Y.; Wei, T.X.; Zhang, Y.R.; Yan, X.F.; Wei, J.H.
Zhongguo Yao Li Xue Bao 14(3): 260-262
1993
ISSN/ISBN: 0253-9756 PMID: 8237406 Document Number: 407906
Effects of ranitidine (Ran) on ventricular refractory period and fibrillation threshold of normal and ischemic ventricle were investigated in pentobarbitone anesthetized rabbits. In saline-treated rabbits, relative refractory period (RRP) and effective refractory period (ERP) were shortened from 132 +/- 24 to 126 +/- 25 ms (n = 10, P < 0.05) and from 118 +/- 22 to 108 +/- 27 ms (n = 10, P < 0.05) in boundary zone of ventricular ischemic regions, respectively. The ventricular fibrillation threshold (VFT) was decreased from 5.5 +/- 1.4 to 2.8 +/- 1.1 V (n = 10, P < 0.01) after coronary artery ligation (CAL). Ran (25 mg.kg-1, i.v.) not only prevented these changes, but also lengthened RRP from 123 +/- 14 to 136 +/- 10 ms (P < 0.05) and ERP from 111 +/- 16 to 126 +/- 12 ms (P < 0.05), and increased VFT from 4.7 +/- 0.8 to 7.4 +/- 1.8 V (P < 0.01) in normal ventricle. The results suggest that Ran may have anti-arrhythmic effects in rabbits.